Acid Orange II

C.I.Name: Acid Orange – 7

C.I. Number: 15510

Application: Dying & Printing of wool, nylon and silk. Also used in paper, leather, biological stain and Indicator Raw

Material: Sulphanilic Acid, Beta Naphthol

Molecular Formula: C₁₄H₁₁N₂O₄S Na

Acid dyes are water-soluble dyes employed mostly in the form of sodium salts of the Sulfonic or carboxylic acids. They are anionic which attach strongly to cationic groups in the fibres directly. They can be applicable to all kind of natural fibers like wool, cotton and silk as well as to synthetics like polyesters, acrylic and rayon. But they are not substantive to cellulosic fibres. They are also used in paints, inks, plastics and leather. Orange acid azo dyes produce an orange-pink color. They are used in coloring foods and drugs and as intermediates for making photosensive dyes and drugs. They are used  as counter stains in histology and cytology and as components of Mallory's acid fuchsine. Acid Fuchsine (acid magenta) is a various mixture of sulfonated fuchsins. There are four of these compounds which have three sulfonic groups each. It is used in Andrade's indicator and in various complex stains to demonstrate collagen fibers red and in smooth muscle in contrast to collagen. It is used as a pH indicator.